Light diffusion fixture



Dec. 8, 1 K AM 2,063,744

LIGHT DIFFUSION FIXTURE Filed June is, 1956 INVENTOR SAM KRA M512 BY W,%

ATTORNEY Patented Dec. 8, 1936 LIGHT DIFFUSIbN FIXTURE Sam Kramer, Elizabeth, N. J., assignor to Dean:

ArtsLighting 00., Inc., New York, N. Y., a corporation of New York Application June 16, 1936, Serial No. 85,450

1 Claim.

My present invention relates to illuminating devices, and more particularly to electrical illuminating fixtures of the light diffusion type.

In the past it has been proposed to employ louvers as light diffusion devices in electrical illuminating fixtures of the suspended type. This prior louver construction has not, however, taken into account such factors as design harmony with the remainder of the fixture; variability of degree of diffusion; simplicity and economy of fabrication and installation. In other words, light diffusion louvers of the past have been provided with the sole purpose of minimizing glare from electrical illuminating fixtures of the ceiling suspended type; this being usually accomplished by disposing the louver elements, constructed of metal, across the illuminating opening of the fixture bowl. This resulted in directing attention to the 'fact that the fixture bowl included a metallic element, and detracted from the general design harmony. Again, the geometric treatment of the louver design did not lend itself to any adjustment of the degree of light diffusion, should such be the desire of the fixture user.

It may, therefore, be stated that it is one of the main objects of my present invention to provide in an electrical illuminating fixture, of the type ordinarily suspended from a ceiling, a lightdifiusing, metallic louver which is of such geometrical configuration, and so treated on its illuminated surface, as to simulate the appearance of glass whereby the metallic louver can be used in association with a glass light bowl without interference with the design harmony of the fixture.

Another important object of the invention is to provide alight diflusion louver, for use in ceiling type illuminating fixtures employing direct illumination, which louver consists of a plurality of concentrically-arranged, metallic, conical frustrums, means being provided to rigidly relate the frustrums in such a manner that when illuminated they act to difiuse the light on one side thereof, andconcentrate the light on the other side; and the surfaces of the frustrums being treated in such a manner that the illumination thereof creates an illusion to a person viewing the fixture that the louver is fabricated from lass.

Still other objects of the invention are to improve generally the simplicity, efilciency and appearance of electrical illuminating fixtures, and more especially to provide such fixtures in an economical manner,

(Cl. 240-48 I The novel features which I believe to be char- I acteristic of my invention are set forth in particularity in the appended claim; the invention itself, however, as to both its construction and method of operation will best be understood by reference to the following description taken in connection with the drawing in which I have indicated diagrammatically a construction whereby my invention may be carried into efiect.

In the drawing:

Fig. l is a front view of a light fixture embodying the invention,

Fig.2 is a bottom view of the fixture, and

Fig. 3 is a partial section taken along line 3 -3 of Fig. 2 looking in the direction of the arrows, showing the louver details viewed as in Fig. 1.

Referring now to the drawing, wherein like reference characters in the different figures designate similar elements,- there is shown in Fig. 1

a type of lighting fixture generally well known in the prior art; it comprises an element I customarily secured to the ceiling, or other support surface, from which the fixture is to be suspended. The usual hollow tube 2 depends from base I,

the latter also being hollow; and bowl support 3 is adjustably secured to the tube 2. The illumination bowl 4 is of the well known type, and is fabricated from translucent glass whereby the light from the bulb 5 (shown in dotted lines) within the bowl is prevented from directly illuminating any of the objects in its vicinity. The frosted, or opalescent, quality of the glass bowl 4 accounts for this; light from bulb 5 can reach objects only indirectly by transmission through the walls and top of the bowl, or by reflection from the surfaces of the conical frustrums of the light diffusion louver 6.

The bowl 4 is rigidly secured to support 3 in the known manner; the threaded bolts I are used to secure the usual curled rim of the circular opening in the bowl top to the support. The bulb 5 is screwed into socket 8 as is conventional; the upper portion 8' of the support 3 can be made hollow to telescope with socket 8. Threaded securing means 9, 9' are then employed to adjust the spacing between the bulb 5 and the louver 5. Of course, the-electrical wiring to the socket B is run through base I and tube 2. By this construction it is possible to adjust the degree of light diffusion caused by louver 6 In assembling the fixture, the support 3 is secured to socket 8, the bulb 5 being screwed in operative position; the bowl, and associated louver, is then attached to support 3 by adjusting bolts 1. It is believed that a sufficient description has been given con-' outer one.

bands l2, H and I extend beyond flange I 6 discerning the general construction of the entire fixture.

The louver 6, as shown in detail in Figs. 2 and 3 consists of a plurality of metallic bands so, H, 02 and I3; each band having the shape of the frustrum of a cone. These bands are concentrically arranged with respect to a common axis passing through the vertical line of intersection of positioning strips Hi and E5. The outer band l3 is provided with a circular flange l6. By means of the flange the louver assembly is rigidly secured to the bowl rim 4'; a plurality of spaced clamps i? being attached to the flange it for this purpose.

Each clamp ll consists of a rectangular strip of metal; a portion ll of which, of a length equal to the width of flange I 6, is aflixed to the upper surface of the flange as by soldering, or in any other well known manner. When the remainder of a strip H is bent into clamping position it cooperates with the portion I? to tightly clamp the rim 4' between portion l1 and upper portion l8. Accordingly, each clamp strip ll should be given a length sufiicient to firmly grip the rim 5' when the strip is in operative position. Four such clamp strips are shown spaced at ninety degree distances; but the number of such clamp strips; manner of spacing; and mode of bending into clamping position are all subject to variation, and dependent on the size of the louver.

When the 'frustrums are in proper relation the upper rims thereof are in a common plane; substantially the entire body of the band I3 being disposed within the interior of bowl 4, and only the flange 16 being exposed. In other words, the louver 6 is positioned within the circular opening in the bowl bottom face by virtue of the attachment between the flange l6 and the periphery of the aforesaid opening. The bands l2, ii and H! are arranged in overlapping relation; as shown in Fig. 3 in detail, the extent of projection of each of the bands from each next preceding band is substantially the same. Further, the flare of each frustrum diifcrs; that of band in being relatively slight in comparison to the others. The degree of flare increases from the inner frustrum to the As shown in Fig. 1, the three inner tances such that a pleasing design results.

The frustrums are secured together in the spaced relation shown by means of strips 54 and I5. These strips are arranged at right angles, each strip being provided with a slot at its midpoint; each slot extending only about half way acros a strip. Thus, the mid-portion of strip is disposed in the slot M of strip M. In this way the top and bottom edges of the strips are re- :pectively in the same planes. The contacting portions of the strips are soldered to each other thereby providing a secure joint at the line of intersection of the strips.

The strips l4 and I5 are rigidly secured to the concentric bands by providing slots in the latter to receive the strips in vertical position. As shown in Fig. 2, each band is provided with four spaced slots 20; these slots are aligned to receive the intersecting strips l4, l5. The strips l4, l5 and slots 20 are soldered at the points of contact thereof; this provides a rigid louver assembly. It will be noted that the strips l4 and I5, when the louver is in assembled position, are located within bowl i, and cannot be seen by an observer looking at the fixture.

The surfaces of the louver elements are sprayed with a material providing a silvery lustre. Preferably this is a dull lustre. For example, a mixture of aluminum powder in lacquer, brought to air gunspraying consistency, can be used for this purpose. When so treated the exposed illuminated surfaces of the louver create a distinct illusion that the latter is constructed of glass. This may be explained by the fact that the light from bulb 5 directly falls on the outer faces of the frus trums; and the inner faces of the latter receive light by reflection from the adjacent outer frustrum faces. The inner face of frustrum ID, of course, receives light directly from bulb 5. Accordingly, it will be seen that the conical configuration of the bands, as well as the silvery lustre, cause the observer to think he is looking at a glass louver since light appears to be passing through the bands themselves. This configuration, at the same time, produces a wide diffusion of light; the pattern of distribution is roughly a cone. Glare, of course, is eliminated by the overlapping action of the louver bands.

The advantages of this novel construction will now be clear. The bowl 4 and louver 6 both appear as a. one piece glass construction when the bulb 5 is operative. This greatly enhances the design value of the fixture, and gives a wider market to a glass-metal fixture. By virtue of the louver construction, and its conical light distribution zone, adjustment of the louver with respect to the bulb 5 will cause a' change in the light intensity. As the bowl is raised, for example, the light intensity emitted through louver 6 is reduced. This adjustment is desirable for many purposes. Hence, the present louver construction has a threefold function: it simulates glass when illuminated making it feasible to'use a glass bowl;

' it makes possible degree of illumination adjustment; and reduction of glare is accomplished even though direct lighting is employed.

While I have indicated and described a system for carrying my invention into efiect, it will be apparent to one skilled in the art that my invention is by no means limited to the particular construction shown and described, but that many modifications may be made .without departing from the scope of my invention, as set forth in the appended claim.

What I claim is:

In an electrical illuminating fixture of the type ordinarily suspended from the ceiling, and which fixture employs a glass bowl housing an electrical bulb, said bowl being provided with an opening in the bottom thereof, a. metallic louver comprising a plurality of bands each having the shape of a conical frustrum, means rigidly maintaining the bands in concentric relation about a common axis, means securing the outer band to the rim of the bowl opening, the bands projecting progressively greater distances from the bowl opening from the outermost band to the innermost hand, all the surfaces of said bands being coated with a material imparting a dull silvery lustre thereto, and

the bands being outwardly flared whereby illumination of the coated surfaces causes the exposed surfaces of the bands to simulate glass.

' SAM KRAMER. 

